MATLAB SIMULINK 3D ANIMATION 5 Manual do Utilizador descarregar pdf (Página 27)

difficult, as the full information about the object shape and structure is lost and

cannot be reconstructed based on the (however complex) tessellated model.

For effective rendering of moving parts, it is recommended that VRML models

are as simple as possible. On the other hand, no or little visible model

degradation is usually required. We need to find a compromise between these

two requirements.

As there are significant performance differences among various computers and

graphic accelerators, there is no firm recommendation as to number of

polygons / triangles suitable for use with Simulink 3D Animation. In order to

assess the model complexity, it is advised to display the resulting VRML file in

the Simulink 3D Animation viewer and observe the viewer response to

navigation. If you can navigate in the virtual scene without any significant

delay, the model is usually suitable for further work. Later on, when we

connect the virtual scene to a Simulink model, there will be available a more

exact measure of suitability – number of frames that are rendered per second

during simulation.

5.1.3. Units Used in Exported Files

VRML length units are meters. In order to scale exported parts correctly in the

virtual scene, it is suitable to export parts using meters. However, if the

exported objects are very small or very large, which means that our planned

virtual scene will be created to some scale, it is suitable to export objects using

different units.

Note: VRML viewers are made to count with dimensions that are

commensurate to us – people, in order to achieve the immersion effect of

virtual reality graphics. Viewers assume that the scene author prepares the

scene so that it can be walked through or examined by a virtual visitor to the

scene (sometimes called the Avatar), whose physical dimensions are used in

calculations for various purposes like collision detection, near object clipping or

terrain following. Avatar dimensions (and also other navigation-specific

parameters like default navigation speed) can be customized using the

NavigationInfo VRML node. Simulink 3D Animation viewer is developed with

the aim that effective navigation in the virtual scene is possible also in scaled

1 2 ... 22 23 24 25 26 27 28 29 30 31 32 ... 42 43

Sem comentários

MATLAB SIMULINK 3D ANIMATION 5 Manual do Utilizador Página 27